Convert Stones to Kilogrammes Instantly
Need the answer now? Use the calculator below to convert stones to kilogrammes in seconds. Enter a weight in stones and the tool will calculate the equivalent value in kilograms using the precise conversion factor:
1 stone = 6.35029318 kilograms
For everyday use, the result is displayed to three decimal places. Below the calculator, you can also find the exact formula, worked examples, guidance for weights written in stones and pounds, and a conversion chart.
Convert Stones to Kilogrammes: Formula, Examples and Practical Guide
If you need to convert stones to kilogrammes, the calculation is straightforward: multiply the number of stones by 6.35029318. One stone is exactly 14 avoirdupois pounds, which makes one stone equal to 6.35029318 kilograms.
For most everyday conversions, rounding the answer to two or three decimal places is sufficient. When accuracy matters, however, it is better to calculate with the full conversion factor and round only the final result.
Quick reference
1 stone (st) = 14 pounds (lb)
1 stone (st) = 6.35029318 kilograms (kg)
1 kilogram ≈ 0.157473 stone
The abbreviation for stone is st, while the internationally recognised symbol for kilogram is kg.
How to Convert Stones to Kilogrammes
Use this formula:
kilograms = stones × 6.35029318
For example, to convert 12 stone to kilograms:
12 × 6.35029318 = 76.20351816 kg
Rounded to three decimal places:
12 st = 76.204 kg
This multiplication works for whole numbers as well as decimal values.
More worked examples
5 stone:
5 × 6.35029318 = 31.7514659 kg
5 st ≈ 31.751 kg
8 stone:
8 × 6.35029318 = 50.80234544 kg
8 st ≈ 50.802 kg
10 stone:
10 × 6.35029318 = 63.5029318 kg
10 st ≈ 63.503 kg
15 stone:
15 × 6.35029318 = 95.2543977 kg
15 st ≈ 95.254 kg
Using the calculator above is the easiest option when the value contains decimals or when you do not want to perform the multiplication manually.
What Is a Stone?
The stone is a traditional unit of mass in the British Imperial system.
One stone is defined as:
1 st = 14 lb
Because one international avoirdupois pound equals exactly 0.45359237 kg, one stone corresponds to exactly:
14 × 0.45359237 = 6.35029318 kg
The stone has a long history in Britain, but today it is most familiar as an everyday way of expressing body weight in the United Kingdom.
For example, someone may describe their weight as:
- 9 stone;
- 11 stone 6 pounds;
- 12.5 stone;
- 14 stone.
NHS England guidance also recognises that home weighing scales may display weight in kilograms, pounds or stone, demonstrating that stone remains an everyday weight unit in the UK.
For trade and packaged goods in Great Britain, however, metric measurements such as grams and kilograms are generally required; imperial measurements may be shown alongside metric values in permitted circumstances.
What Is a Kilogramme?
A kilogramme, more commonly spelled kilogram internationally, is a metric unit of mass with the symbol kg.
One kilogram contains:
1 kg = 1,000 grams
Kilograms are used internationally in science, industry, health records, sport, travel, shipping and everyday measurement.
The spellings kilogramme and kilogram refer to the same unit. The spelling does not change the conversion.
Where Is the Stones-to-Kilograms Conversion Most Useful?
Although kilograms are used internationally, stones remain familiar in British everyday life. This creates several situations where a conversion is useful.
Body-weight records
A person may know their weight from a home scale in stones but encounter a form, fitness tracker or other service that asks for kilograms.
For example:
11 st = 69.853 kg
Converting the units lets the same measurement be understood in both systems.
Fitness and sport
Training apps, gym equipment and sports data often use kilograms even when someone normally thinks of their body weight in stones.
The conversion can therefore be useful when recording progress or comparing measurements between systems.
International travel and relocation
People travelling or moving between the UK and countries that use metric units almost exclusively may need to translate familiar stone measurements into kilograms.
Comparing information from different sources
A UK source may give a person’s weight in stone, while an international source may use kilograms. Converting one measurement allows a direct comparison.
Converting Stones and Pounds to Kilograms
Body weight in the UK is often written using both stones and pounds, for example:
12 st 4 lb
In this case, do not treat 12.4 stone as the same measurement. Four pounds is not four-tenths of a stone.
Because:
1 stone = 14 pounds
you can calculate the total pounds first.
For 12 st 4 lb:
12 × 14 = 168 lb
Then add the remaining 4 lb:
168 + 4 = 172 lb
Finally:
172 × 0.45359237 = 78.01788764 kg
Therefore:
12 st 4 lb ≈ 78.018 kg
This distinction is important because confusing pounds with decimal fractions of a stone can produce an incorrect result.
Decimal Stones and Stones Plus Pounds Are Different
Consider these two values:
12.5 st
and
12 st 5 lb
They do not mean the same thing.
Half a stone equals:
0.5 × 14 = 7 lb
Therefore:
12.5 st = 12 st 7 lb
This is why it is important to check whether a measurement uses a decimal stone value or the traditional st + lb format before converting it.
Why Accurate Stone-to-Kilogram Conversion Matters
For a rough mental estimate, using:
1 st ≈ 6.35 kg
is usually convenient.
For an accurate conversion, however, Easy Unit Convert uses the full factor:
1 st = 6.35029318 kg
The difference is small for one stone, but rounding too early can produce larger differences when converting higher values.
For example:
Using 6.35:
100 st × 6.35 = 635 kg
Using the precise factor:
100 st × 6.35029318 = 635.029318 kg
The best practice is therefore to calculate with the full conversion factor and round only the result.
For information about how conversion factors and calculations on this website are checked, see our Accuracy & Editorial Policy.
Common Mistakes When Converting Stones to Kilograms
A few simple mistakes can lead to incorrect results.
Dividing instead of multiplying.
To convert stones into kilograms, multiply by 6.35029318.
Using pounds as decimal stones.10 st 5 lb is not the same as 10.5 st.
Rounding too early.
Use the full conversion factor during the calculation and round the final result.
Confusing stone with pounds.
One stone contains 14 pounds, so the units are not interchangeable.
Forgetting the unit.
Always label the result with kg so it is clear which measurement system is being used.
Related Weight Converters
If you are working between Imperial and metric weight units, you may also find these useful:
- Convert Kilograms to Stones
- Convert Stones to Pounds
- Convert Pounds to Kilograms
- Convert Kilograms to Pounds
Stones to Kilogrammes Conversion Table
The following table uses the precise conversion factor 1 st = 6.35029318 kg. Results are rounded to three decimal places for readability.
| Stones (st) | Kilogrammes (kg) |
|---|---|
| 1 | 6.350 |
| 10 | 63.503 |
| 20 | 127.006 |
| 30 | 190.509 |
| 40 | 254.012 |
| 50 | 317.515 |
| 60 | 381.018 |
| 70 | 444.521 |
| 80 | 508.023 |
| 90 | 571.526 |
| 100 | 635.029 |
Frequently Asked Questions
One stone equals exactly 6.35029318 kilograms. For most everyday purposes, this can be rounded to 6.35 kg.
Multiply the number of stones by 6.35029318.
For example:
10 st × 6.35029318 = 63.5029318 kg
So 10 stone is approximately 63.503 kg.
12 stone equals:
12 × 6.35029318 = 76.20351816 kg
Therefore:
12 st ≈ 76.204 kg
Yes. One stone is defined as 14 avoirdupois pounds.
Since one pound equals exactly 0.45359237 kg:
14 lb = 6.35029318 kg
No. Kilogramme and kilogram refer to the same metric unit, with the symbol kg. “Kilogram” is the spelling most commonly used internationally today.
Stone is a traditional British weight unit and remains familiar in everyday discussions of body weight. Modern UK scales may display kilograms, pounds or stones, although metric units are standard for many official and commercial uses.
Convert the stones to pounds first, add the remaining pounds, then multiply the total number of pounds by 0.45359237.
For example:
12 st 4 lb = 172 lb
172 × 0.45359237 ≈ 78.018 kg
No.
Half a stone equals 7 pounds, because:
0.5 × 14 = 7
Therefore:
12.5 st = 12 st 7 lb
not 12 st 5 lb.
For a quick estimate, multiply the number of stones by 6.35. For a more accurate result, use 6.35029318, or enter the value into the calculator at the top of this page.
